Ferrierite is of interest as a molecular sieve zeolite due to channels formed by 10-membered rings parallel to the c-axis (1,2). It occurs naturally in the exchange varieties, per 1 Al content as Na.sub.0.23 K.sub.0.04 Mg.sub.0.36 at Kamloops Lake, B.C. with quartz and calcite (1,3): as Na.sub.0.21 K.sub.0.49 Mg.sub.0.06 Ca.sub.0.09 at Lovelock, Nevada with mordenite and tridymite (4); as Na.sub.0.03 K.sub.0.06 Mg.sub.0.35 Ca.sub..12 per 1 (Al + Fe'") at Vicenza, Italy with calcite (5) and as Na.sub.0.41 K.sub.0.32 Mg.sub.0.14 at Agoura, California with quartz, calcite and clinoptilolite (6).
Synthesis of Sr-ferrierite has been reported by Barrer and Marshall (7) in the temperatue range 340.degree.-380.degree. C from aqueous gels of composition SrO.sup.. Al.sub.2 O.sub.3.sup.. 7-9SiO.sub.2. Hawkins (8) synthesized Sr- and Ca-ferrierite in the temperature range 350.degree.-370.degree. C from co-precipitating gels using nitrates of calcium, strontium and aluminum and Ludox colloidal silica sol. Senderov (9) reported the synthesis of Na-ferrierite within the temperature range studied of 150.degree.-350.degree. C from silica gel, sodium aluminate and sodium hydroxide in mixtures giving a 10 silica:1 alumina ration with slight excess of Na.sub.2 O and the sum of oxides was about 10% of the total water content. Na-ferrierite was reported as a coexisting phase with mordenite by Sand (10) but no conditions for its synthesis were given.
All of these syntheses either involve high temperatures, uncommon starting materials or lack of detail as to published process parameters.
These and other difficulties experienced with the prior art processes have been obviated in a novel manner by the present invention.
It is therefore, an outstanding object of the invention to provide a process for synthesizing a ferrierits, an intermediate port zeolite that can be used to separate molecules of 6.2 A diameter from large molecules.
Another object of this invention is the provision of a process for synthesizing ferrierite which involves readily available starting materials, reasonably low temperatures and short times.
With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of steps and the details of the composition hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.